This invention relates to a continuous process for the extraction of metal and non-metal values from minerals and particularly, but not exclusively, metal values from metal ores and concentrates.
Extraction from ores and concentrates is usually performed by leaching with a reagent such as a mineral acid to convert the contained metal values to metal salts which are soluble in the reagent. After removal of the remaining insoluble solids of the ore or concentrate the metal values can then be extracted from the liquid phase.
It is known that the rate of reaction of the leaching process falls with increase in concentration of the reaction product--the metal salt--and that the reaction reaches equilibrium when a given concentration is achieved. It is therefore not usually possible to leach out all the contained metal values and it is necessary either to forego the extraction of the remaining metal or to treat the ore again after the reaction product so far generated has been removed. In either case, leaching efficiency is lost.